This is a note to let you know that I've just added the patch titled

    mm: numa: guarantee that tlb_flush_pending updates are visible before page 
table updates

to the 3.12-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     
mm-numa-guarantee-that-tlb_flush_pending-updates-are-visible-before-page-table-updates.patch
and it can be found in the queue-3.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From [email protected]  Tue Jan  7 10:38:11 2014
From: Mel Gorman <[email protected]>
Date: Tue,  7 Jan 2014 14:00:47 +0000
Subject: mm: numa: guarantee that tlb_flush_pending updates are visible before 
page table updates
To: [email protected]
Cc: [email protected], [email protected], [email protected], Mel Gorman 
<[email protected]>, [email protected]
Message-ID: <[email protected]>

From: Mel Gorman <[email protected]>

commit af2c1401e6f9177483be4fad876d0073669df9df upstream.

According to documentation on barriers, stores issued before a LOCK can
complete after the lock implying that it's possible tlb_flush_pending
can be visible after a page table update.  As per revised documentation,
this patch adds a smp_mb__before_spinlock to guarantee the correct
ordering.

Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
---
 include/linux/mm_types.h |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -478,7 +478,12 @@ static inline bool mm_tlb_flush_pending(
 static inline void set_tlb_flush_pending(struct mm_struct *mm)
 {
        mm->tlb_flush_pending = true;
-       barrier();
+
+       /*
+        * Guarantee that the tlb_flush_pending store does not leak into the
+        * critical section updating the page tables
+        */
+       smp_mb__before_spinlock();
 }
 /* Clearing is done after a TLB flush, which also provides a barrier. */
 static inline void clear_tlb_flush_pending(struct mm_struct *mm)


Patches currently in stable-queue which might be from [email protected] are

queue-3.12/mm-numa-clear-numa-hinting-information-on-mprotect.patch
queue-3.12/sched-numa-skip-inaccessible-vmas.patch
queue-3.12/mm-numa-avoid-unnecessary-disruption-of-numa-hinting-during-migration.patch
queue-3.12/mm-compaction-respect-ignore_skip_hint-in-update_pageblock_skip.patch
queue-3.12/mm-clear-pmd_numa-before-invalidating.patch
queue-3.12/mm-fix-tlb-flush-race-between-migration-and-change_protection_range.patch
queue-3.12/mm-numa-ensure-anon_vma-is-locked-to-prevent-parallel-thp-splits.patch
queue-3.12/mm-numa-do-not-clear-pte-for-pte_numa-update.patch
queue-3.12/mm-hugetlb-check-for-pte-null-pointer-in-__page_check_address.patch
queue-3.12/mm-numa-serialise-parallel-get_user_page-against-thp-migration.patch
queue-3.12/mm-munlock-fix-deadlock-in-__munlock_pagevec.patch
queue-3.12/mm-numa-guarantee-that-tlb_flush_pending-updates-are-visible-before-page-table-updates.patch
queue-3.12/mm-numa-avoid-unnecessary-work-on-the-failure-path.patch
queue-3.12/mm-page_alloc-revert-numa-aspect-of-fair-allocation-policy.patch
queue-3.12/mm-mempolicy-correct-putback-method-for-isolate-pages-if-failed.patch
queue-3.12/mm-numa-do-not-clear-pmd-during-pte-update-scan.patch
queue-3.12/mm-numa-call-mmu-notifiers-on-thp-migration.patch
queue-3.12/mm-munlock-fix-a-bug-where-thp-tail-page-is-encountered.patch
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